1. Field of the Invention
The present invention relates to an optical coordinate measuring device using a probe.
2. Description of Related Art
An optical coordinate measuring device is provided with a probe for designating a measurement position. An arbitrary position of a measurement target is designated as a measurement position by the probe, and coordinates of the measurement position are calculated. By calculating coordinates of a plurality of measurement positions on the measurement target, a size of a desired portion of the measurement target is measured.
JP 06-511555 A describes a system for point by point measurement of spatial coordinates, which includes a data processor, a contact probe, and an angle sensor. The contact probe is provided with a plurality of point light sources in addition to a contact point. The angle sensor is provided so as to allow observation of an essential portion of a measurement target and allow observation of the plurality of point light sources of the contact probe.
A spatial direction from the angle sensor toward each light source is recorded. Based on the recorded spatial direction, a position and an orientation of the contact probe with respect to the angle sensor are calculated by a data processor. The position of the contact probe and a position of the contact point are associated with a position of the measurement target.
In the system for point by point measurement in JP 06-511555 A, there is a possibility that the positional relationship among the plurality of light sources minutely changes. In this case, it becomes impossible to accurately specify the position of the contact probe. As a result, the accuracy in measurement of the coordinates deteriorates.